#!/usr/bin/env python3
#
# Copyright (C) 2020 VyOS maintainers and contributors
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 or later as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# rename WWAN (wirelessmodem) serial interface from non persistent ttyUSB2 to
# a bus like name, e.g. "usb0b1.3p1.3"

import os

from sys import exit, argv
from vyos.configtree import ConfigTree

if __name__ == '__main__':
    if len(argv) < 2:
        print("Must specify file name!")
        exit(1)

    file_name = argv[1]
    with open(file_name, 'r') as f:
        config_file = f.read()

    config = ConfigTree(config_file)
    base = ['interfaces', 'wirelessmodem']
    if not config.exists(base):
        # Nothing to do
        exit(0)

    for wwan in config.list_nodes(base):
        if config.exists(base + [wwan, 'device']):
            device = config.return_value(base + [wwan, 'device'])

            for root, dirs, files in os.walk('/dev/serial/by-bus'):
                for file in files:
                    device_file = os.path.realpath(os.path.join(root, file))
                    if os.path.basename(device_file) == device:
                        config.set(base + [wwan, 'device'], value=file, replace=True)

    try:
        with open(file_name, 'w') as f:
            f.write(config.to_string())
    except OSError as e:
        print("Failed to save the modified config: {}".format(e))
        exit(1)
